The study of direct torque control used in the startup process of ALA rotor motor

The axially laminated anisotropic (ALA) rotor motor is a competitive candidate for high performance variable speed drives. However, the online startup of the motor is not applicable for lacking of starting cages. In the inverter-fed applications, in order to keep the synchronism between the rotor and the flux, a sensor is always required to detect the position of the rotor. But the utilization of sensor will increase the cost and deteriorate the stability, or even be forbidden in some applications. In this paper, the direct torque control (DTC) scheme is employed to control the ALA rotor motor. The characteristics of basic DTC scheme are stated and the discrete space voltage vector modulation (DSVM) is introduced. Finally, the experimental investigation on a DSP-based drive system is presented. It´s validated that the motor with the proposed control strategy has satisfactory starting and operating performance.